[031/119] pps: events reporting fix up

Greg KH
2009-12-07T00:30:25Z

[-- Attachment #1: pps-events-reporting-fix-up.patch --]
[-- Type: text/plain, Size: 2682 bytes --]

2.6.31-stable review patch. If anyone has any objections, please let us know.

------------------
From: Rodolfo Giometti <giometti@linux.it>

commit 276b282e904f690dc930f9bc946110651f297669 upstream.

PPS events must be recorded according to PPS's mode settings.

If a process asks for (i.e.) capture-assert events only, when the PPS
client calls the pps_event() function to save the current PPS event, we
should verify the event type and then discard unwanted ones.

Also, without this patch userland processes waiting for a specific PPS
event (assert or clear but not both) may be awakened at wrong time.

Signed-off-by: Rodolfo Giometti <giometti@linux.it>
Tested-by: William S. Brasher <billb958@door.net>
Tested-by: Reg Clemens <clemens@dwf.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/pps/kapi.c | 20 +++++++++++++++-----
1 file changed, 15 insertions(+), 5 deletions(-)

--- a/drivers/pps/kapi.c
+++ b/drivers/pps/kapi.c
@@ -271,6 +271,7 @@ void pps_event(int source, struct pps_kt
{
struct pps_device *pps;
unsigned long flags;
+ int captured = 0;

if ((event & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR)) == 0) {
printk(KERN_ERR "pps: unknown event (%x) for source %d\n",
@@ -293,7 +294,8 @@ void pps_event(int source, struct pps_kt

/* Check the event */
pps->current_mode = pps->params.mode;
- if (event & PPS_CAPTUREASSERT) {
+ if ((event & PPS_CAPTUREASSERT) &
+ (pps->params.mode & PPS_CAPTUREASSERT)) {
/* We have to add an offset? */
if (pps->params.mode & PPS_OFFSETASSERT)
pps_add_offset(ts, &pps->params.assert_off_tu);
@@ -303,8 +305,11 @@ void pps_event(int source, struct pps_kt
pps->assert_sequence++;
pr_debug("capture assert seq #%u for source %d\n",
pps->assert_sequence, source);
+
+ captured = ~0;
}
- if (event & PPS_CAPTURECLEAR) {
+ if ((event & PPS_CAPTURECLEAR) &
+ (pps->params.mode & PPS_CAPTURECLEAR)) {
/* We have to add an offset? */
if (pps->params.mode & PPS_OFFSETCLEAR)
pps_add_offset(ts, &pps->params.clear_off_tu);
@@ -314,12 +319,17 @@ void pps_event(int source, struct pps_kt
pps->clear_sequence++;
pr_debug("capture clear seq #%u for source %d\n",
pps->clear_sequence, source);
+
+ captured = ~0;
}

- pps->go = ~0;
- wake_up_interruptible(&pps->queue);
+ /* Wake up iif captured somthing */
+ if (captured) {
+ pps->go = ~0;
+ wake_up_interruptible(&pps->queue);

- kill_fasync(&pps->async_queue, SIGIO, POLL_IN);
+ kill_fasync(&pps->async_queue, SIGIO, POLL_IN);
+ }

spin_unlock_irqrestore(&pps->lock, flags);